. >> pope benedict xvi addressed catholics during an emotional sendoff today. vinita nair is in vatican city where tens of thousands packed st. peter's square to witness history. >> reporter: pope benedict xvi arrived in st. peter's square for his final general audience smiling and waving from the popemobile. he spent about 15 minutes saying hellos, stopping to admire one of the youngest in the crowd. aides assisted the 85-year-old as he walked up to the platform. in a clear strong voice, the pope thank the faithful from the bottom of his heart. the holy father acknowledged his eight-year reign had rough spots saying at times that it seemed like the lord was sleeping. benedict retires tomorrow and plans to dedicate the rest of his years to prayer. >> i was deeply freightful for the understanding -- grateful for the understanding, support and prayers of so many of you. >> reporter: an estimated 150,000 people cheered and waved signs thanking the pope for his service. some wiped away tears. >> opportunity to say good-bye to someone who really saved our lives. >>